Medical instrument

ABSTRACT

A hydraulically actuated medical instrument includes an elongated shaft having proximal and distal ends, a hydraulically actuated end effector at the distal end of the shaft and a fluid flow path extending through the shaft to the end effector. The end effector may be directly manually operated by way of a handle located at the proximal end of the shaft or remotely, for example, via robotic controller. Articulation joints may be provided along the shaft, between the shaft and end effector or handle, or elsewhere. The hydraulic actuation of the present invention permits multiple axis instrument articulation, miniaturization and simplified instrument fabrication.

PRIORITY CLAIM

This application is a divisional application of U.S. application Ser.No. 10/990,651, filed Nov. 17, 2004, now U.S Pat. No. 7,503,474, whichis a continuation of application Ser. No. 09/942,236, filed on Aug. 29,2001, now U.S. Pat. No. 6,830,174, which claims the benefit ofprovisional application Ser. No. 60/229,076, filed Aug. 30, 2000. Eachof the above applications is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates in general to medical instruments suitablefor endoscopic or laproscopic applications, and capable of passingthrough a trocar or similar device. More specifically, the presentinvention relates to a novel hydraulically actuated medical instrumentsuitable for stapling or other desired endoscopic or laproscopicapplications.

Surgical instruments, such as staplers, graspers, scissors, coagulatorsand the like, suitable for endoscopic or laproscopic applications inwhich the device is inserted through a cannula or trocar, are wellknown. As described in more detail below, the present invention, in itsmost preferred embodiment, is directed to an endoscopic staplerparticularly suited for minimally invasive surgery for isolating theleft atrial appendage on human hearts.

In U.S. Pat. No. 5,306,234, incorporated by reference herein, Dr. W.Dudley Johnson described a minimally invasive procedure for isolatingthe left atrial appendage of the human heart from the associated atrium.It is known that during atrial fibrillation blood may pool in the leftatrial appendage. When blood pools in the atrial appendage, clots mayform. Upon the resumption of normal beating, these clots may be ejectedfrom the appendage and enter the blood flow to other parts of the body.If the clots enter the arteries of the brain or heart, stroke or heartattack may result.

In his patent, Dr. Johnson described a procedure for isolating the leftatrial appendage without requiring open heart surgery, as was previouslyused. Specifically, he described entering the chest cavity betweenselected ribs with a minimally invasive opening or openings, whilemaintaining the sternum and ribs intact. While this procedure holdsgreat promise, there remains a need for instruments suitable forconveniently and efficiently carrying out this procedure. The presentinvention provides such an instrument, although it also has aspects andfeatures not limited to the particular procedure described in Dr.Johnson's patent or to stapling apparatus procedures in general.

Also, endoscopic medical instruments are often of complicatedconstruction, especially when the instrument is articulated to allow thehandle and/or end effector to pivot or rotate. Typically, a mechanicallinkage extends between the handle and end effector to allow operatoractuation of the end effector. When the instrument is of the type thatpermits articulation, the mechanical linkage must accommodate thearticulation. This often results in a design that is relativelycomplicated, that is costly to manufacture and/or that may stillexperience limitations regarding the degree or direction ofarticulation.

SUMMARY OF THE CLAIMED INVENTION

The present invention is generally embodied in a medical device of atype suitable for endoscopic or laproscopic procedures and whichincludes, in one embodiment, an elongated shaft having a proximal endand a distal end, an end effector at the distal end of the elongatedshaft, and a handle portion at the proximal end of the elongated shaft.In accordance with the present invention, the end effector ishydraulically actuated and at least one hydraulic fluid flow pathextends between the handle portion and the end effector through theelongated shaft.

In accordance with another aspect of the present invention, the medicalinstrument may include at least one articulation joint at a selectedlocation in or between the handle portion and the end effector. Thearticulation joint may be located between the elongated shaft and thehandle portion, between the elongated shaft and the end effector orelsewhere along the shaft or within the handle or end effector if sodesired. More than one articulation joint may be provided to allowgreater motion options and to make the instrument particularly wellsuited to carry out the atrial appendage isolation procedure describedabove. For that purpose, the end effector is preferably biased in alateral direction to specially position it for the atrial appendageprocedure. It should be noted, however, that although the presentinvention is described below in terms of a device particularly wellsuited for the atrial appendage isolation procedure, it includes aspectsor features that are not limited to the particular illustrated device orto that particular procedure.

A benefit of the present invention in its preferred embodiment is thatthe degree and direction of articulation are essentially unlimited. Toallow articulation while providing fluid communication between thehandle and end effector, at least the portion of the hydraulic fluidflow path in proximity to the articulation joint is flexible. Morespecifically, the fluid flow path may be flexible along its entirelength or may be rigid in certain areas and flexible in proximity to thearticulation joint to provide fluid flow communication along the flowpath without substantially impairing articulation.

The present invention is particularly advantageous in a medicalinstrument having an end effector that has multiple motions oroperations, Such a medical instrument may comprise a plurality (2, 3 ormore) of independent closed hydraulic fluid flow paths extending betweenthe handle portion and the end effector, which each flow pathcontrolling a different operation or movement.

Where the end effector is for stapling tissue, for example, it may havea pair of relatively movable jaws, and a pair of hydraulic actuators—onefor opening and/or closing the jaws and one for firing the staples. Insuch an embodiment, a pair of independent closed hydraulic flow pathsmay extend between the handle and the end effector, and the handleportion may include a separate hydraulic pressure source communicatingwith each fluid flow path. Each pressure source is controllable by theuser for changing the hydraulic pressure within each of the flow pathsfor selective actuation of the end effector.

In such a medical instrument, the use of flexible hydraulic systems forend effector actuation is of substantial advantage, particularly incombination with multiple articulation joints. The complicatedstructures and relationships that would be required for directmechanical control mechanisms through the articulation joints areessentially eliminated, and the instrument fabrication can be greatlysimplified and miniaturized.

Although the present invention may be used with a variety of endeffectors, tissue stapling is one of its anticipated uses. For tissuestapling, the instrument preferably employs a dual-hydraulic system forcontrolling the action of the end effector. For example, as a stapler,one closed hydraulic system is employed for opening and/or closing thestapler jaws, and a separate and independent closed hydraulic system isemployed to effect the stapling operation.

The end effector preferably includes a plurality of staples carried byone jaw and a staple anvil carried by the other jaw. The staples may becontained in a removable supply cartridge and the hydraulic actuator maybe adapted to force the staples from the respective jaw and against theanvil of the other jaw. To effect firing of the staples, the endeffector may have a linearly extensible balloon engageable with amovable staple ejector, such as a cam or wedge, to forcibly expel thestaples from the jaw upon increase of hydraulic pressure in the balloon.The staples are expelled with enough force to bend over the ends of thestaples when they engage against the anvil to clinch tissue that isclamped between the stapler jaws. After the stapling action is complete,the balloon is positively mechanically returned to a retracted ordeflated position for the next stapling operation. For purposes of theremainder of this description and any claims, “balloon” is intended tobe given a broad generic interpretation that comprehends any deviceexpansible under hydraulic pressure, whether a flexible resilient memberor otherwise.

To effect opening and closing of the jaws of the end effector, the endeffector may include another hydraulic actuator employing a novelpiston-cylinder arrangement substantially fully enclosed in the anviljaw of the end effector. The actuator employs a longitudinally moveablepiston and a connecting linkage associated with the piston andcooperative with each of the first and second jaws to move them towardone another upon increase of hydraulic pressure in the hydraulicactuator. Preferably, the jaws are biased to an open position, such asby a spring, and upon the release of hydraulic pressure the jaws wouldautomatically open.

To control jaw clamping, the pressure source in the handle communicatingwith the jaw closing actuator may be a hydraulic cylinder blockcommunicating with the relevant hydraulic fluid flow path. To change thepressure of the hydraulic fluid, a piston is slidably movable within thecylinder block between at least a higher pressure position and a lowerpressure position. The piston may be moved by a lever that is pivotallymounted on the handle portion and engageable with the piston so thatoperator actuation of the lever directly changes the hydraulic fluidpressure.

The medical instrument may further include a trigger cooperative withone of the pressure sources for changing the hydraulic pressure sourcein one of the fluid flow paths. As with the lever, the trigger mayoperate on a piston slidably received in a cylinder block (which may beseparate from or one-piece with cylinder block employed by thelever-actuated piston) for changing the pressure in one of the hydraulicflow paths. In a stapling instrument, the trigger may operate to effectthe stapling function after the end effector jaws are closed by thelever. A safety latch engageable with the trigger holds the trigger in alower pressure, retracted and inaccessible position until the jaws areclosed and locked in the desired position. The safety may then bereleased, and the trigger deployed, by a positive deliberate action bythe surgeon. When the trigger is pulled—the hydraulic pressure in thefluid flow path is increased, causing the balloon to expand, forcing awedge or cam forward, and causing staples to be forced from one jaw andagainst an anvil on the other jaw.

In accordance with a preferred aspect of the present invention, theseparate clamping and firing hydraulic systems of the stapler employ acommon, one-piece cylinder block. In combination with a unique firingtrigger and clamping lever arrangement and piston arrangement, a compactand efficient handle arrangement that is easy to assemble and includesseveral built-in safety features, as discussed below, is provided.

Other aspects of the present invention, as set forth in the followingdetailed description and claims, are found in the end effector assemblyand in the handle portion alone. Although described in terms of acomplete instrument suitable for insertion through a trocar or the like,various features of the present invention found in the end effector andin the handle portion may have application in other instruments and withdifferent style handles and end effectors without departing from thepresent invention.

DESCRIPTION OF DRAWINGS

FIG. 1 is vertical cross-sectional view of an endoscopic staplinginstrument employing the various features and aspects of the presentinvention. This figure shows the handle assembly, barrel or shaftassembly and end effector assembly. This cross-sectional view isslightly tilted toward the viewer to provide a slightly downwardperspective.

FIG. 2 is an exploded perspective view of the handle assembly and thebarrel assembly of the instrument of FIG. 1.

FIG. 3 is an exploded perspective view of the end effector assembly (theclamping and stapling jaws) of the instrument of FIG. 1.

FIG. 4 is a vertical cross-sectional view of the handle assembly andarticulation joint between the handle and barrel of the instrument ofFIG. 1, with the jaws in the fully open position, and with portionspertaining to the staple operation removed for better illustration ofthe clamping operation.

FIG. 5 is an enlarged vertical cross-sectional view of the end effectorportion of the instrument of FIG. 4, with the jaws fully open, and withportions relating to stapling removed for better understanding of theclamping operation.

FIG. 6 is a vertical cross-sectional view of the handle assembly of FIG.4, but with the jaws at an intermediate position.

FIG. 7 is an enlarged vertical cross-sectional view of the end effectorportion of FIG. 5, but with the jaws at an intermediate position.

FIG. 8 is a vertical cross-sectional view of the handle assembly of FIG.4, but with the jaws at a fully closed position.

FIG. 9 is an enlarged vertical cross-sectional view of the end effectorportion of the instrument of FIG. 5, but with the jaws at a fully closedposition.

FIG. 10 is an enlarged perspective view of the handle assembly of FIG. 1in a fully clamped position and with portions removed to better show therelationship between the clamping lever and firing trigger.

FIG. 11 is a perspective view of the handle of the instrument of FIG. 1,with portions removed to better illustrate the firing trigger and safetylatch, and with the firing trigger in the undeployed position.

FIG. 12 is a perspective view of the handle of FIG. 11, taken from adifferent angle, showing the safety latch and the firing trigger in theundeployed, retracted position.

FIG. 13 is an enlarged side view of the handle of FIG. 11, and of thefiring trigger and safety latch in particular, with the firing triggerin the deployed position.

FIG. 14 is a perspective view of the handle of FIG. 11, taken from adifferent angle to better illustrate various aspects of the firingtrigger and safety latch.

FIG. 15 is a side view of the handle of the instrument of FIG. 1, withparts removed to illustrate the firing trigger and safety latch, withthe firing trigger in the fired position.

FIG. 16 is an enlarged perspective view of a portion of the handleassembly of the instrument of FIG. 1, taken from the back side of theinstrument as depicted in FIG. 1 and illustrating, among other things, afiring lockout feature that prevents staple firing until the instrumentis fully clamped.

FIG. 17 is a view comparable to FIG. 16, but showing the trigger lockoutin a released position.

FIG. 18 is a perspective view of the end effector jaws of the instrumentof FIG. 1 in the closed position.

FIG. 19 is a perspective view of the lower end effector jaw of thepresent invention in FIG. 18, with the upper jaw removed.

FIG. 20 is a perspective view of the lower jaw of the end effector, withportions removed as compared to FIG. 19 for better illustration.

FIG. 21 is a perspective view of portions of the lower end effector jaw,with portions removed as compared to FIG. 20 for better illustration.

FIG. 22 is a perspective view of portions of the lower end effector jawwith portions removed as compared to FIG. 21 for better illustration.

FIG. 23 is a perspective view of portions of the lower end effector jaw,comparable to FIG. 22, but with the balloon expanded to illustrate theballoon position after staple firing.

FIG. 24 is a side view of the lower end effector jaw after staplefiring.

FIG. 25 is a vertical cross-sectional view taken along lines 25-25 ofFIG. 24.

FIG. 26 is a perspective view of a portion of the balloon retractionassembly of the instrument of FIG. 1 for retracting the balloon afterstaple firing.

FIG. 27 is an enlarged view of a portion of the distal portion of FIG.26, for better illustration of the balloon and parts of the balloonretraction assembly.

FIG. 28 is a further enlarged view of a portion of the balloonretraction of assembly of FIG. 26.

FIG. 29 is an enlarged cross-sectional view of the handle portion andfirst articulation joint connecting the handle portion to the barrelportion of the instrument shown in FIG. 1, with the jaws of the endeffector in an open position.

FIG. 30 is a cross-sectional view of a barrel portion of the instrumentof FIG. 1, illustrating a portion of the mechanism for positivelyretracting the actuator balloon after staple firing. The positionindicated in FIG. 30 is the position with the balloon fully retractedbefore staple firing.

FIG. 31 is an enlarged cross-sectional view of the end effector portionand distal end of the barrel portion of the instrument of FIG. 1,showing the jaws in the fully open position.

FIG. 32 is an enlarged cross-sectional view of the handle portion andfirst articulation joint or gimbal connecting the handle portion to thebarrel portion of the instrument shown in FIG. 1 with the jaws of theend effector in a closed position.

FIG. 33 is an enlarged cross-sectional view of the end effector portionand distal end of the barrel portion of the instrument of FIG. 1 showingthe jaws in the fully clamped position.

FIG. 34 is an enlarged cross-sectional view of the handle portion andfirst articulation joint or gimbal connecting the handle portion to thebarrel portion of the instrument shown in FIG. 1 with the jaws of theend effector in a closed position and the staples fired

FIG. 35 is an enlarged cross-sectional view of the end effector portionand distal end of the barrel portion of the instrument of FIG. 1 showingthe jaws in the fully clamped position and staples fired.

FIG. 36 is a cross-sectional view of a barrel portion of the instrumentof FIG. 1, illustrating a portion of the mechanism for positivelyretracting the actuator balloon after staple firing. The positionindicated in FIG. 36 is the position with the balloon expanded to itsfull length after staple firing.

FIGS. 37 and 38 are cross-sectional views, respectively, of the stapleactuation balloon in the inflated and deflated condition.

FIG. 39 a is a top view of an instrument of the present inventionemploying distal jaws that are pivotable in different directions, andshowing the jaws pivoted at a right angle to the barrel.

FIG. 39 b is a top view of the instrument of FIG. 39 a with the jawspivoted at less than 90° to the barrel.

FIG. 39 c is a side view of the instrument of FIG. 39 a with the jawsclosed.

FIG. 39 d is a perspective view of the distal end of the instrument ofFIG. 39 b.

FIG. 39 e is a side view of the distal end of the instrument of FIG. 39c with the jaws open.

DESCRIPTION OF ILLUSTRATED INSTRUMENT

FIG. 1 is an overall cross-sectional view of a surgical staplinginstrument, generally at 100, employing the present invention andparticularly suited for endoscopic or laproscopic isolation of the leftatrial appendage. As shown in FIGS. 1-3, the illustrated instrument 100includes a proximal handle portion or assembly, generally at 102, adistal end effector or implement portion or assembly 104 and anintermediate barrel or shaft portion or assembly, generally at 106,connecting the handle and the effector portions. In this form, thepresent invention is particularly well suited for endoscopicapplication, where the end effector is inserted through a trocar or likedevice and is operated by the handle portion, which remains outside thepatient.

Although the present invention is illustrated in the context of anendoscopic stapler, the present invention is not, in its broaderaspects, limited to a stapler or to a particular type of end effector.Accordingly, it should be understood that the following description ofthe present invention in its present and preferred stapler constructionis for the purposes of illustration, and not for the purposes oflimiting various aspects of the present invention to the specificstructure or form shown in the drawings.

Turning first to a brief overview of the illustrated instrument, asshown in FIG. 2, the handle portion 102 is divided into two halves orshells 108 that, when joined, house or mount the various mechanical andhydraulic parts involved in clamping the effector jaws together andfiring the staples. In brief, each handle shell 108 includes a fixedgrip area 110, a body portion 112 and a distal spherical portion 114that cooperates with other parts to provide a swivel or gimbal actionbetween the handle assembly and the barrel assembly 106, as will bedescribed in more detail later. The handle may be made of any suitablematerial such as rigid, injection molded plastic or the like.

The barrel portion 106 comprises a hollow elongated cylindrical barrel116 preferably made of suitable metal, although rigid plastic may alsobe used. The barrel is sufficiently small to allow introduction of theinstrument through the lumen of a trocar or other introductory deviceemployed in the surgical procedure for access through the skin of thepatient to the surgical site. The barrel 116 contains the fluid flowtubing 118 and 120 of the hydraulic actuation systems for, respectively,closing the distal effector jaws and firing staples. In addition, thebarrel contains a balloon retractor subassembly, generally at 122 inFIG. 2, that positively returns an actuator balloon to its retractedposition after staple firing, as also will be discussed in more detaillater.

The preferred effector or implement end 104 of the instrument may beseen in FIGS. 1 and 3. In the illustrated embodiment, the effector endor implement is in the form of a pair of jaws for clamping and staplingtissue. The effector end includes a lower jaw 124 and an upper jaw 126pivotally attached to the lower jaw. The lower jaw contains a prefilledstaple cartridge that are ejected by hydraulic action. The upper jawincludes the anvil, which includes a series of curved convex surfacesfor forming the staple ends over to clench the tissue gripped betweenthe jaws. Of course, the jaw positions may be reversed and other endeffector arrangements may be employed without departing from the presentinvention. For example, the jaws may include multiple rows of stapleswith a cutting element located between the rows to separate tissue uponstapling. The end effector could also include electrodes for radiofrequency sealing, or could comprise scissor blades for cutting tissue.These are just a few of the additional possible applications of theinstrument of the present invention.

The end effector assembly of FIGS. 1 and 3 is mounted to the distal endof the barrel 116 at an articulation joint, generally at 126, whichallows relative side to side pivoting of the end effector jaws afterthey protrude through the distal end of the introduction trocar. In thepreferred embodiment, the end effector is spring-biased at thearticulation joint to extend proximately 30 degrees in the direction outof the plane of the paper in FIG. 1. This feature of the illustratedinstrument places the jaws in a preferred position for clamping andsealing the left atrial appendage of a human heart after entry betweenthe ribs, in the procedure described in U.S. Pat. No. 5,306,234 to Dr.Johnson.

The Handle Assembly

Turning now to FIG. 2, as pointed out earlier, the jaw clamping andstaple firing of the present invention are hydraulically controlled, andeach is controlled by a separate hydraulic system. The handle portion orassembly 102 mounts a hydraulic cylinder block 130 that includes a pairof parallel bores 132 and 134 for receiving, respectively, a piston forjaw clamping 136 and a piston for staple firing 138. The proximal end ofeach piston includes a gear rack for rack and pinion type cooperationwith the gear teeth of separate clamping and for firing members. Coilsprings 140 and 142 bias each piston toward a proximal, low pressureposition.

It is contemplated that the hydraulic fluid used in these systems willbe water or a combination of water-alcohol mixture to prevent the growthof organisms within the hydraulic fluid. Incompressible liquids are thepreferred hydraulic fluid, but other liquids, and possibly even gases,could also be used as the hydraulic fluid, if so desired.

The clamping piston is moved forward, in a distal direction, by pivotingof clamp lever 144 toward the fixed pistol grip 110. Clamp lever 144 ispivotally mounted on cylindrical boss 146 that extends from the insidesurface of handle shell 108. The clamp lever includes a raised arcuatesegment that carries a series of gear teeth 148 on its upper surface,which engage with the teeth of the clamping piston gear rack 136,forming a rack and pinion arrangement. Upon pivoting of the clampinglever rearwardly, the clamping piston is forced forward or distally intobore 132, pressurizing the liquid located within the closed hydraulicsystem for the clamping action.

To lock the clamp lever in the clamped position, the handle assemblyincludes a release button 150. The release button has a proximalexternal thumb release tab 152 and a distal nose 154 that cooperateswith upper surfaces 156 of the clamp lever that flank the gear teeth148. The release button 150 is pivotally mounted on a cylindrical boss158 (extending from the inside surface of housing shell 108)intermediate the thumb tab and the nose piece so that downward pressureon the thumb tab raises the nose piece. Coil spring 160 is attached tothe release button to bias the nose downwardly. As will be described inmore detail later, when the clamp lever is pulled to the clampingposition, the nose of release button 150 falls into a locking notch 162in the clamp lever to hold it in the clamped position. After the jawsare clamped, the next action required of the surgeon is to fire thestaples so that they extend through and clench the tissue that isgripped between the closed jaws. To carry out this action, the handleassembly includes a firing trigger 164 and a safety latch 166. Thefiring trigger is also pivotally mounted on boss 146 of the handle. Ascan be seen in FIGS. 2, 12 and 10, in that order, the firing trigger hasa pair of spaced-apart side walls 168. The upper end of the clampinglever is located within the space or slot between the side walls of thefiring trigger, and the boss 146 extends through both the firing triggerand clamping lever.

The firing trigger is biased by torsion spring 170 to an extended firingposition. However, until firing is needed, the trigger is held inretracted position within the handle by the safety latch 166. The safetylatch 166 includes laterally extending wings 172 that extend throughaccess openings or windows 174 in each side of the handle body 112.

The safety latch is also pivotally mounted to the body and biased by aspring wire 176 to a latched position, where it retains the firingtrigger in an inaccessible retracted position within the handle untilthe surgeon wishes to fire the staples. At that time, the firing triggeris deployed by pushing on the end of one of the wings 172 that extendsthrough side window in the handle. This action pivots the safety latchto a release position, allowing the firing trigger to deploy downwardly,due to the bias of torsion spring 170. The surgeon may then squeeze thefiring trigger, causing gear teeth 258 on the upper surface of thefiring trigger to move the staple firing piston forward, pressurizingthe hydraulic fluid within the staple firing hydraulic circuit. Thedetails of the various clamping and staple firing actions is shown moreclearly in later drawings, where extraneous parts or pieces have beenremoved to clarify an understanding of the different operations of theillustrated device.

The Effector Assembly

Turning now to the distal or effector end of the instrument 100, theparts of the distal end may first be seen in FIG. 3, an exploded view.

The lower jaw 124 includes a bent u-shaped sheet metal channel 180 thatincludes an inclined slot 182 in each side wall and a pivot opening 184in each side wall, where the upper jaw is pivotally attached to thelower jaw. The proximal end of the channel 180 is also formed into anarticulation joint or knuckle, generally at 128, for pivotally joining,via pivot pin 129, with the distal end of the barrel or shaft 116.

The lower jaw includes a replaceable staple supply cartridge, generallyat 186, which fits into a u-shaped bent metal receiver 188 locatedwithin channel 180. The staple cartridge includes a side recess 189 forreceiving a locator tab on the upper jaw where the jaws are clampedtogether. The lower jaw also includes a balloon housing 190 for housingthe staple actuation balloon 192. The balloon terminates in a roundedballoon tip 194 for engaging against a wedge 196 in the staplecartridge. Axial expansion of the balloon forces the wedge through thestaple cartridge, the sloped forward surface of wedge 196 forcing thestaples upwardly out of the cartridge.

The upper jaw 126 of the end effector includes an anvil body 198 thathas pivot openings 200 for pivotal attachment to the lower jaw pivotopenings 184 by pivot pin 202. The anvil body 198 also includes a pairof slots 204 that cooperate with inclined slots 182 in the lower jaw,via slide pin 206, for relative opening and closing of the jaws. Theanvil body further includes a staple cartridge locator tab 207, forinsertion into the side recess 189 of the staple cartridge forpositively locating the staple cartridge when the jaws close.

The upper jaw 126 also includes a nose piece 208 that has a central bore210 for receiving piston 212. The piston 212 cooperates with a linkage214 to open and close the jaws. More specifically, piston rod 216extends through linkage eye 218 and through a coil spring 220 and intothe nose piece bore 210 (with bushing 211 closing the proximal end ofthe nose piece bore except for a small hydraulic fluid port in thebushing). The linkage 214 includes pivot openings 222 that cooperate,via slide pin 206, with the slots 204 in the anvil body and inclinedslots 182 in the lower jaw channel, as will be described in more detaillater. Finally, the upper jaw includes an anvil former 224 which hasconcave pockets for receiving and bending over the staples to clenchtissue gripped between the jaws, and a torsion spring 226 for laterallybiasing the jaws to a angle position relative to the barrel 116.

The Barrel Assembly

Referring to FIG. 2, the barrel or shaft assembly 106 includes thebarrel or shaft 116 which houses the hydraulic tubing 118 and 120 forthe closing and firing systems and the balloon retractor subassembly122. As mentioned earlier, the barrel or shaft 116 is a hollow,cylindrical, elongated tube, and is preferably made of metal, althoughsuitably strong plastic may also be used. The proximal end of the barrel116 includes opposed slots 228 for attachment to swivel joint 298between the handle and barrel. The distal end of the barrel has upperand lower pivot openings 232 for receiving pivot pin 129 that joins thebarrel and jaws to form the articulation joint 128.

The balloon retraction subassembly 122 located within the barrelincludes a balloon retractor tube 234 extending longitudinally withinthe barrel and closed at each end by a bushing 236. Hydraulic fluid fromthe staple firing piston communicates with the interior of the balloonretractor tube through tubing 120 that is attached to a hydraulic fluidport in the proximal bushing 236. The hydraulic fluid path extendsthrough the distal end bushing 236 to an extension of tubing 120 thatcontinues to the proximal end of balloon 192, located in the lower jawof the effector assembly.

The balloon retractor tube 234 encloses, as best seen in FIGS. 26-28, acable cap 238 attached to the proximal end of a retractor wire 240.Retractor wire 240 extends through the distal bushing 236, through theextension of tubing 120 and through the balloon to the balloon tip 194.Coil spring 242 extending between the distal bushing of the retractortube and the cable cap 238 biases the end cap to a proximal position,which corresponds to a balloon retracted position. With thisarrangement, expansion of the balloon pulls, via wire 240, cable cap 238in a distal direction, compressing coil spring 242. When the hydraulicforce is reduced after staple firing, the force of the compressed coilspring pushes the cable cap rearwardly (proximally), pulling the wire240 and thus the balloon to a retracted or deflated position.

The Clamping Action

FIGS. 4-9 show cross-sectional views of the handle portion and endeffector portion with respect to the clamping operation, with parts andpieces relating to the firing action removed for better understanding ofthe clamping action.

FIGS. 4-5 show the handle assembly and effector assembly as they are inthe jaws open position. Turning to FIG. 4, the handle assembly 102 isshown there in cross-sectional view, illustrating the clamp lever 144pivotally mounted on boss 146, the hydraulic cylinder block 130, and theclamping piston 136 which includes a gear rack at its proximal end.Flexible tubing 118, which may be plastic, silicone or other suitablematerial, extends from the clamping piston bore 132 to the distal endjaws for effecting the clamping action. The tubing is flexible at leastin the vicinity of or in proximity to the articulation joints so as notto substantially interfere with or impair articulation of the joint.Compressed coil spring 140 extends between the hydraulic cylinder block130 and flange 244 located on the piston. Coil spring 140 biases pistontoward a proximal, low pressure position, so as to bias the effectorjaws in an open position.

In the position illustrated in FIGS. 4-5, the jaws are fully open, theclamp lever 144 is fully extended, and the clamping actuation piston isin the position fully to the right in the non-pressurized proximalposition. The distal nose 154 of the release button 150 rests on thesmooth upper surfaces 156 of the clamp lever 144 (See FIG. 10). Coilspring 160 is in tension, pulling the nose of the release buttondownwardly. As better seen in FIGS. 1 and 10, the distal or nose end ofthe release button is slotted. The clamping piston gear rack is slidablyreceived within the nose piece slot, and the nose piece thereforeprevents lateral, side-to-side shifting of the piston gear rack.

Turning to FIG. 5, showing the end effector jaws in the open position,comparable to FIG. 4, the effector jaws are shown in cross-sectionalview, without a staple cartridge, to better illustrate the clampingfunction. As shown there, the anvil body 198 is pivotally mounted bypivot pin 202, which extends through pivot openings 184 of the lower jawchannel and 200 in the upper jaw anvil body. Slide pin 206 extendsthrough slots 182 in the lower jaw channel, slots 204 in the upper jawanvil body, and through pivot openings 222 of the linkage 214. Piston212 is located within the bore 210 of the nose piece 208. The pistonincludes an o-ring 246 located in an o-ring slot 248 around thecircumference of the piston to seal against the leakage of hydraulicfluid.

The proximal end of the nose piece is closed by a bushing 211, to whichthe hydraulic tubing 118 is attached. The fluid space 250 locatedbetween bushing 211 and piston 212, in normal operation, will be filledwith hydraulic fluid. Upon pressurization of the hydraulic fluid, thepiston will be moved distally or forwardly (to the left in FIG. 5). Aswill be recalled, the piston rod 216 extends through the eye 218 of thelinkage 214, and movement of the piston to the left also pushes thelinkage to the left.

The forward or distal end of the nose piece is slotted on the undersideto receive the eye 218 of linkage 214. As the piston moves to the left,action of the slide pin 206 moving along slots 204 in the upper jawanvil body and 182 in the lower jaw channel pull the slots together,closing the jaws. Movement of the piston also compresses the coil spring220 that extends between an inner shoulder 252 on the nose piece and thelinkage eye 218. Accordingly, in the event of failure of the hydraulicclamping system, the spring 220 will move the piston 212 to a jaw-openposition.

FIGS. 6 and 7 show the handle assembly 102 and end effector assembly 104in the position where the jaws are partially closed. As can be seen inFIG. 6, the clamp lever 144 has moved partially toward the fixed pistolgrip 110. The rack and pinion gear arrangement between the clampingpiston 136 and clamp lever gear teeth 148 has moved the clamping pistonslightly distally or to the left in FIG. 6, pressurizing the hydraulicfluid within the bore 132 of the hydraulic cylinder block 130. Inasmuchas this is a closed hydraulic system full of normally incompressibleliquid, little movement is required to generate very high pressureswithin the hydraulic system. This increased pressure is transmittedthrough the tubing 118 to the piston 212 located in the upper jaw at thedistal end of the instrument.

Turning to FIG. 7, increased hydraulic pressure through the tubing 118and bushing 211 has moved the piston 212 slightly in the distaldirection (to the left in the drawing) pulling the linkage 214 in adistal direction, and moving slide pin 206 distally along slots 204 inthe upper jaw anvil body and 182 in the lower jaw channel. This actionof the linkage and pin has drawn the upper and lower jaws of the distalend together.

FIGS. 8 and 9 show the instrument 100 with the jaws 124 and 126 fullyclosed or clamped. As seen in FIG. 8, the clamp lever 144 has now beenpivoted fully against the pistol grip 110. Nose end 154 of the releasebutton 150 has dropped into the locking notch 162 in the upper area ofthe clamp lever, preventing the clamp lever from rotating clockwise,unless the thumb release tab 152 is depressed. Coil spring 160, which isin tension, holds the release button in this locked position.

In the fully clamped position, the gear teeth 140 on the upper end ofthe clamp lever 144 have advanced the clamping piston 136 morecompletely in the compressed direction (to the left in the drawing),creating increased pressure in the clamping hydraulic circuit andfurther compressing piston coil spring 140.

As shown in FIG. 9, the increased pressure of the hydraulic liquid,communicated through the tubing 118 and into the bore of the nose piece208 has moved the piston 212 in upper jaw 126 distally. As a result, thepiston 212 has pushed the linkage 214 toward the distal end of the jawand the slide pin 206 to the distal end of the slots 204 in the upperjaw anvil body and 182 in the lower jaw channel. This action brings thejaws to the fully closed or clamping position. Again, coil spring 220 iscompressed, biasing the piston to the low pressure or jaws openposition.

When it is desired to open the jaws, the above described action isreversed. The thumb tab 152 on the release button 150 is depressed,raising the nose 154 of the release button from the lock-out notch 162in the clamp lever, and allowing the clamp lever to rotate clockwise tothe open position. The bias of the compressed springs 220 in the upperjaw and 140 in the handle force the clamping piston 136 outwardly of thebore 130 in the hydraulic cylinder block to a low pressure position,where it was initially, as seen in FIG. 4 for example, and the jaws openby the reverse movement of slide pin 206 in the slots 204 in the upperjaw anvil and 182 in the lower jaw channel.

The Stapling Action

Turning now to the stapling action, the hydraulic circuit of thestapling action may be seen in FIGS. 12-26. As was pointed out earlier,the hydraulic system for the firing circuit has, at the proximal end,the staple firing piston 138, which is slidably received within bore 134of the hydraulic cylinder block 130. As with the clamping hydrauliccircuit, the firing hydraulic circuit is a closed circuit, pre-filledwith essentially non-compressible liquid, although other fluid and evencompressible gas may be employed if desired. Hydraulic fluid isconducted through flexible tubing 120, balloon retractor tube 234,tubing 120 extension and into the balloon 192, so that the tubing islocated in proximity to the joints to allow articulation withoutsubstantial interference and without complicated mechanical structuresfor transmitting control actions to the end effector. Both clamping andfiring pistons include one or more o-rings to seal against therespective bore to prevent leakage of hydraulic fluid.

The handle mechanism by which the staple firing sequence occurs isperhaps best seen in FIGS. 11-15, which are views of the inside of thehandle, with parts relating to the clamping action removed. Turningfirst to FIG. 11, the firing trigger 164 is shown in the retracted andundeployed position, where it is held by the safety latch 166 until thesurgeon takes the positive step, after being satisfied with theclamping, to deploy the firing trigger. As may be seen in FIG. 12, thefiring trigger is pivotally mounted on the same boss 146 as the clamplever 144. More specifically, the firing trigger includes a pair ofspaced apart circular side or end walls 168, one of which includes gearteeth 258 for cooperation with the gear rack of the staple-firing piston138, and the other of which mounts the torsion spring 170, which biasesthe trigger to the deployed position. In the completed assembly (SeeFIG. 10), the upper end of the clamp lever 144 is located and capturedbetween the spaced-apart circular walls 168 of the firing trigger,rotating freely relative to the firing trigger on the boss 146. As shownin FIG. 14, the rack of the staple firing piston is constrained againstupward movement by a horizontal plate 260. The horizontal plate alsoincludes an aperture 262 for receiving one arm of the torsion spring170. The other arm of the torsion spring is captured in a slot 264provided in the side face of the firing trigger.

To hold the firing trigger in a retracted and inaccessible positionuntil after the surgeon is satisfied with the clamping, the presentinvention employs the safety latch 166. As seen in FIGS. 1 and 12, thesafety latch 166 includes a vertical wall or body 266 which mounts, atits upper end, opposed pivots 268 that extend into hollow bosses 270 ofthe handle, allowing the safety latch to pivot or swing about thosepivot points. As seen in FIG. 13, a tongue or tab 272 protrudesproximally from the face of the safety latch for engagement with awindow 274 (as best seen in FIG. 14) in the safety latch trigger. Oneend of spring wire 176 is attached, as seen in FIG. 14, to partition 276of the handle. The other end of the spring wire is located in a slot 278in the back side of the safety latch body 266. Thus, the spring wirebiases the safety latch counterclockwise, so that the tongue 272 entersthe trigger window 274 when the trigger is moved to a retractedposition.

As described briefly earlier, the safety latch includes a pair of wings172 extending laterally from the body 266, and through windows 174 inthe side walls of the handle. When the surgeon is satisfied with theclamping action, he or she may, by pushing on the end of the wingsprotruding through the window, pivot the safety latch clockwise toremove the latch tongue 272 from the firing trigger window 274, andallow the firing trigger to deploy under the biasing force of thetorsion spring 170.

In the deployed position, the firing trigger is accessible to thesurgeon for executing the firing action of the staples. Similar to theclamping action, pulling on the trigger causes, through the meshing ofgear teeth 258 and the teeth of the staple firing piston rack, thestaple firing piston to move distally to compress the hydraulic fluid inthe firing piston bore 134 and to compress the coil spring 142 thatsurrounds the firing piston. As hydraulic pressure is increased by themovement of the piston in the handle, the increased pressure istransmitted to the balloon 192 through the hollow tube 120, the balloonretractor tube 234, and tubing extension.

The staple firing sequence in the distal lower jaw is most easilyunderstood by reference to FIGS. 18-25. FIG. 18 is a perspective view ofthe end effector, which shows both the top and bottom jaws 124 and 126of the preferred embodiment of the present invention. In FIG. 19, theupper jaw is removed, and only the lower jaw with the staple cartridge186 remains. In that figure, the inclined slots 182 in the channel 180are readily visible, as is the pivot opening 184 by which the upper jawis pivotally attached to the lower jaw. The articulation joint 128 andpivot pin 129 mounting the end effector to the distal end of the barrelare also visible in FIG. 19.

In FIG. 20, the channel is removed, and we can now see the receiver 188,containing the staple cartridge 186, and also the balloon housing 190. Aballoon housing tab 280 is located on each side of the balloon housing190 for snap interfit in side apertures 284 in channel 180 (see FIG.19).

FIG. 21 shows the distal end of the lower jaw with the receiver andstaple cartridge, in large part, removed. In this figure, tubing 120,which conveys the hydraulic fluid to the balloon, is shown entering therear or proximal end of the balloon housing 190. The rear of the balloonhousing also includes an arcuate or cutout area for accommodating thepivot pin 202 that pivotally mounts the lower and upper jaws together.

The balloon housing 190 has a generally U-shaped cross-sectional shape,forming a channel for receiving the deflated or retracted balloon. Theconvex, hemispherically shaped tip 194 of the balloon may be seen at thedistal end of the housing in FIG. 21. FIG. 21 also shows the cam orwedge 196 which, when forced axially through the staple cartridge,ejects the staples. The proximal end of the wedge is generallyspherically concave in shape to receive the spherically convex tip ofthe balloon. The wedge also includes a ramp or cam surface 284.

Within the staple cartridge, as is well known in the prior art, eachstaple 286 is located atop a driver 288, and the drivers are aligned ina generally axial direction. As the wedge is forced forward or distallythrough the cartridge, the drivers are forced up the ramp surface of thewedge, ejecting the staples and forcing them against the anvil formerthat is located in the upper jaw.

The balloon 192 has a fluted wall which allows it to be repeatedlyexpanded and retracted. As shown in FIG. 22, the balloon is in theretracted position. When the firing trigger is pulled, and the staplefiring piston increases hydraulic pressure in the firing circuit, theballoon expands axially, as shown in FIG. 23, forcing the wedge throughthe cartridge and firing the staples into and through the tissue andforming the ends of the staples over to clench the tissue gripped therebetween.

FIGS. 37 and 38 shows a vertical side cross-sectional view of theballoon when expanded and retracted, and showing the fluted or foldedaccordion configuration of the balloon.

There is yet one additional safety feature associated with the firing ofthe staples in the instrument 100. Turning to FIG. 16, a depending hook290 is located at the proximal end of the staple firing piston 138. Thathook is engaged by a raised tab 292 on the nose 154 of the releasebutton 150 until the jaws are clamped. This interference prevents axialmovement of the staple firing piston until after the jaws have beenfully clamped. It may be recalled from FIG. 8, that after the clampinglever is fully retracted, the nose of the release button falls into thelocking notch 162 in the upper surface of the clamp lever 144. When thatoccurs, the raised tab on the release button drops out of engagementwith the staple firing piston (see FIG. 17), allowing the piston to bemoved by the firing trigger. Until such time, however, as the releasebutton drops into the notch in the clamp lever, which occurs only in thefully clamped position, inadvertent or accidental firing of the staplesis prevented.

Articulation Joints

It was previously noted that the present invention employs, asillustrated, a swivel or gimbal between the handle portion and thebarrel or shaft portion. In the illustrated embodiment, as best seen inFIG. 4, this swivel or gimbal is in the nature of a ball and socketjoint 294. As can be seen in FIG. 2, the distal end of each half of thehandle includes a hemispherical portion 114, such that when the twohandle halves are joined, a ball 296 is formed at the distal end of thehandle portion.

Slidably mounted over the ball is a socket 298, also formed by joiningtwo halves, which includes a distal bore 300 for fixedly receiving theproximal end of the barrel or shaft 116. The proximal inside surface ofthe socket is curved to match the hemispherical shape of the ball,forming a relatively tight but still slidable frictional fit between theball and socket. For locking engagement of the proximal end of the shaftinto the socket, each socket half includes a inwardly extending tab 302,which enters a mating slot 228 in the proximal end of the barrel. Thisserves to lock the barrel or shaft in a fixed position relative to thesocket. Accordingly, with this construction, the handle may be pivotedrelative to the barrel or shaft in any direction for up to about 20degrees.

As clear from the description, the end effector of the present inventionis also articulated relative to the barrel or shaft. As best seen inFIGS. 3 and 19, the proximal end of the lower jaw channel 180 is bentinto a series of tabs 304, each of which includes a pivot opening 306 inaxial alignment with the others. The distal end of the barrel, as alsoseen in FIG. 3, includes upper and lower axially aligned pivot openings232. Pivot pin 129 extends through aligned pivot openings 232 in thedistal end of the barrel and the aligned pivot openings 306 in the benttabs of the lower jaw channel 180. This forms a hinged type of joint,allowing pivoting movement of the jaws laterally left and right relativeto the barrel.

For particular application of this device to the isolation of the atrialappendage, torsion spring 226 is located on the vertical pin, biasingthe jaws at a lateral angle of about 30 degrees relative to the barrel,although other degrees of biasing may be employed, if desired. Thespring allows the jaws and barrel to be in alignment as they passthrough the trocar in the patient and to the treatment site, but as thedistal end of the instrument emerges from the trocar, the jaws move tothe angled position to which it is predisposed by the torsion spring.

The end effector may also be mounted for articulation in otherdirections, such as vertically or at another angle. Also, thearticulation joint between the barrel and end effector may be a gimbalor ball and socket type joint, such as used between the barrel andhandle, for 360° of articulation. With such a joint, control wiresextending from the handle, through the barrel and to the end effectorcould be used to control the direction and amount of articulation of theend effector to effect precise changes or adjustments to the position ofthe end effector, as may be required for particularly delicate medicalprocedures.

FIGS. 39 a-e show an alternative embodiment of the present invention. Aswith the instrument described above, the version shown in FIGS. 39 a-eincludes a handle portion 102, end effector portion 104 and barrelportion 106. In this embodiment jaws 300 and 302 are pivotally attachedat 304 for opening and closing in a scissor-like movement. In addition,each jaw has a terminal portion that is separately pivotable at 308 toallow pivoting of the terminal portion of the jaws at up to a rightangle with respect to the barrel portion 106 (as shown in FIG. 39 a).With this construction, the jaws may be in general alignment with thebarrel for passage through a trocar, and then pivoted to any desiredposition at the surgical site.

As can be seen from the above description, the present invention hasseveral different aspects and features, which are not limited to thespecific device shown in the attached drawings or to the specificprocedure for which it is intended. Various of these features may beembodied in other devices for carrying out other procedures, includingbut not limited to stapling, cutting, grasping, coagulating or othersurgical procedures.

Although shown in a manual form, for direct control by the surgeon, thepresent invention is also applicable in robotically controlledprocedures. The hydraulic actuation of the present inventionparticularly lends itself to small diameter instruments, multi-axisarticulation and large force (e.g., clamping or cutting force)generation, which are not only advantageous in manual applications butare also particularly useful in robotic applications, where theinstrument operation is remotely controlled through a robotic controllermodule or unit.

In a robotic application, for example, the end effector assembly couldbe attached, by way of an elongated shaft, with a remote hydraulicpressure source. The hydraulic pressure source (which may includemultiple independent hydraulic pressure sources) could be remotelycontrolled via electronic or electro-mechanical controller operated byprogrammable microprocessor alone or in combination with manual controlor voice control commands or both, as already known in the art of remoterobotic control.

1. A hydraulically actuated end effector for an endoscopic medicalinstrument, the end effector comprising: a first hydraulic actuatorresponsive to changes in hydraulic actuation pressure to effect a firstselected action and a second hydraulic actuator responsive to changes inhydraulic actuation pressure to effect a second selected action, saidfirst or second hydraulic actuator comprising an extensible balloon toeffect the selected action; and a retraction member operably connectedto the balloon and configured for movement by a biasing member inresponse to changes in hydraulic actuation pressure to move the balloonto a retracted position.
 2. The end effector of claim 1, furthercomprising first and second relatively moveable jaws.
 3. The endeffector of claim 2, wherein the first hydraulic actuator is adapted tomove the first and second jaws toward and away from one another.
 4. Theend effector of claim 3, wherein each of the first and second jaws eachcomprises a scissor blade for cutting tissue.
 5. The end effector ofclaim 2, wherein the first hydraulic actuator includes a longitudinallymoveable piston and a connecting linkage associated with the piston andcooperative with each of the first and second jaws to move them towardone another upon increase of hydraulic pressure in the first hydraulicactuator.
 6. The end effector of claim 2, further comprising a pluralityof staples carried by the first jaw and a staple anvil carried by thesecond jaw.
 7. The end effector of claim 2, wherein the extensibleballoon is adapted to force the staples from the first jaw and againstthe anvil of the second jaw.
 8. The end effector of claim 7, wherein thefirst jaw includes a moveable staple ejector and the extensible balloonis a linearly extensible balloon engageable with the staple ejector toforce the staples from the first jaw upon increase of hydraulic pressurein the balloon.
 9. The end effector of claim 2, wherein the retractionmember is a wire.
 10. The end effector of claim 2, wherein the biasingmember is a spring.
 11. The end effector of claim 10, wherein anincrease in hydraulic actuation pressure compresses the spring.
 12. Ahydraulically actuated end effector for an endoscopic medicalinstrument, the end effector comprising: a first hydraulic actuatorresponsive to changes in hydraulic actuation pressure to effect a firstselected action and a second hydraulic actuator responsive to changes inhydraulic actuation pressure to effect a second selected action, saidfirst or second hydraulic actuator including an extensible balloonoperably connected to a retraction member wherein the retraction memberis movable from a retracted position to effect a selected action,wherein the retraction member is biased to the retracted position by abiasing member.
 13. The end effector of claim 12, further comprisingfirst and second relatively moveable jaws.
 14. The end effector of claim13, wherein the first hydraulic actuator is adapted to move the firstand second jaws toward and away from one another.
 15. The end effectorof claim 12, wherein the retraction member is movable from its retractedposition upon an increase of hydraulic actuation pressure and is movabletowards its retracted position upon a decrease of hydraulic actuationpressure.
 16. A hydraulically actuated end effector for an endoscopicmedical instrument, the end effector comprising: first and secondrelatively moveable jaws; a first hydraulic actuator responsive tochanges in hydraulic actuation pressure to move the first and secondjaws toward and away from one another; and a second hydraulic actuatorincluding an extensible balloon positioned in one of said jaws, theballoon being operably connected to a retraction member and together theballoon and retraction member are movable in response to changes inhydraulic actuation pressure to effect a selected action and are biasedto a retracted position by a biasing member.
 17. The end effector ofclaim 16, wherein the first hydraulic actuator includes a longitudinallymoveable piston and a connecting linkage associated with the piston andcooperative with each of the first and second jaws to move them towardone another upon increase of hydraulic pressure in the first hydraulicactuator.
 18. The end effector of claim 16, wherein the extensibleballoon is adapted to force a plurality of staples from the first jawagainst an anvil of the second jaw.
 19. The end effector of claim 16,wherein the retraction member is a wire and the biasing member is aspring.
 20. The end effector of claim 16, wherein the balloon isconfigured to linearly extend within said one of said jaws upon anincrease of hydraulic actuation pressure and to be linearly compressedupon a decrease of hydraulic actuation pressure.